Envelop



No. 62l,l52. I Patented Mar."|4, I899. J. SCH'AUB.

ENVELOP.

(Application filed Dec. 11, 1896.)

(No Model.)

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NITED STATES JACOB SCHAUB, OF SALT LAKE CITY, UTAH.

ENVELOP.

SPECIFICATION forming part of Letters Patent No. 621,152, dated March 14, 1899.

Application filed December 11, 1896. Serial No. 615,329. (No model.)

T0 at whom it may concern:

Be it known that 1, JACOB SoHAUB, a citizen of the United States, residing at Salt Lake City, in the county of Salt Lake and State of Utah, have invented certain new and useful Improvements in Envelops; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain new and useful improvements in envelops, the object of the same being to provide an envelop which cannot be opened without detection by either a penknife, pencil, or other pointed instrument or by the application of moisture either in the form of steam or hot or cold water.

A further object of the invention is to provide an envelop which is adapted to be used for second-class matter in which the sealingflap is neatly held in close contact with the outer surface of the back of the envelop, retaining the contents of the envelop in place without the necessity of inserting the sealingflap into the body of the envelop itself.

My invention is an improvement in that class of envelops in which a pocket is formed in the bottom flap for the reception of the tongue of the sealing-flap.

In the drawings forminga part of this specification, Figure 1 represents a face view of the blank from which my envelop is made. Fig. 2 is a rear view of the envelop, with the bottom and side flaps shown in their closed positions and the sealing-flap in its open position. Fig. 3 is a rear view of the envelop having all the parts closed and sealed. Fig. 4 is a vertical central cross-section on the line m x of Fig. 3.

Like reference-numerals indicate like parts in the difierent views.

The blank 1 is creased along the four lines shown, forming the front or face of the envelop of a homogeneous portion of the paper or other material. The back is formed by the bottom flap 2 and the side flaps 3 and 4., which are pasted together, as clearly shown in Fig. 2 of the drawings. The bottom flap 2 has a pocket 5 therein, which when the parts are closed is located just below the connecting ends of the side flaps 3 and 4. The said pocket 5 is formed by folding inwardly the bottom flap 2 along the line 5 and then folding'the same outwardly along the line 5", as clearly shown. The sealing-flap 6 has a tongue '7 formed upon it, which is adapted to be inserted into the pocket formed by the double fold 5 and be held in place by means of mucilage or other like material applied to the inner surface of said sealing-flap along its outer edge. The outer surface of the tongue 7 hasafilm 8, of shellac, rubber, or other suitable waterproof material, applied to it to prevent moisture from coming in contact with the mucilage on the inner surface of said tongue. (The said film or waterproof material may extend any suitable distance above the upper end of the pocket formed by the fold 5 and may, if desired, be extended entirely around the outer edge of the sealingflap opposite the gummed portion thereof.

An envelop constructed as herein described. is adapted to receive any kind of mail-matter that it may be desired to place in it, and when sealed with the tongue 7, fitting within the pocket formed by the double fold 5, it is absolutely impossible to getat the contents of the envelop, either by means of a knife or other pointed instrument or by the application of moisture to the gummed portion ofthe sealing-flap.

hen it is desired to use my improved envelop for second-class mail-matter, the tongue 7 may be inserted into the pocket in the back of the envelope without moistening the gummed portion of the sealing-flap, and the same is thereby held securely in place.

The device is extremely simple in construction, efiective for the purpose for which it was designed, and can be produced at a cost but little in advance of the cost of the ordi-' nary envelop now in use.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

. 1 As an improved article of manufacture, the envelop herein described, which is formed of the bottom flap 2, having an inward fold forming the pocket 5, the two side flaps 3 and 4, overlapping each other and also said bottom flap,and separated at their lapped ends from the aforesaid pocket by a narrow space, the mucilaged sealing-flap 6, having the tongue 7, made of less width than the aforesaid space and thus adapted to enter the pocket, as shown and described.

2. As an improved article of manufacture, the envelop herein described, formed of the integral blank having the sealing-flap with adhesive coat on its inner side and the central tongue, 7, provided with an insoluble coat, 8, on its outer side, the bottom flap, 2, having the fold-pocket, 5, and the side flaps, 3 and 4, overlapping and adhering to each other and said bottom flap, and separated at their ends from the aforesaid pocket, as shown and described, whereby the flap 6 may be sealed down upon the side flaps 3 and 4, and its tongue sealed within the pocket, but is protected from unsealing by the exterior application of moisture, as specified.

3. An envelop having a bottom flap 2 

